Effect of multivalent ion doping on magnetic, electrical, and dielectric properties of nickel ferrite nanoparticles

The nanoscale spinel structured ferrites co-doped with multi-valence ions are of great interest and proving to be promising for numerous applications. In light of this, herein we report tetravalent titanium ions (Ti⁴⁺) and divalent zinc ions (Zn²⁺) co-doped nickel ferrites with generic formula of NiFe_{2 - 2x}Ti_xZn_xO₄ (x = 0.00 ≤ x ≤ 0.20 in step of 0.05). The sol gel self combustion method in assistance with citric acid as fuel was employed to prepare the samples. The X-ray diffraction (XRD) analysis with Rietveld refinement was performed to confirm the single-phase cubic spinel structure. The sphere type grain morphology of the samples was revealed by SEM images. The compositional studies carried out by EDAX showed desired formation of the composition with absence of impurities in the samples. The characteristics bands belonging to the spinel ferrites were appeared in IR spectra confirming the successive sample forming. The different surface parameters including surface area and pore volume was estimated using Brunauer-Emmett-Teller (BET) analysis. The low coercive nature with soft magnetism was observed with the co-doping as revealed by M-H plots. The electric and dielectric parameters showed decrementing behaviour with increment in Ti⁴⁺-Zn²⁺ co-doping. This study outcome signifies that the Ti⁴⁺-Zn²⁺ co-doping in nickel ferrites could be a prominent for many nanoelectronics applications.